espressomd-users
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Constraint violated by particle


From: Kai Szuttor
Subject: Re: Constraint violated by particle
Date: Wed, 28 Oct 2020 10:17:14 +0100

please attach a minimal not working example reproducing your issue


Am 28.10.2020 um 09:50 schrieb Ahmad Reza Motezakker <armot@kth.se>:



​​Dear Kai,


Before sending my email, I tried to change the directions of the normal vectors but it gave me the same error. To clarify it, Attached please find the schematic of the way that i have defined the constraints and LB boundaries and their normal vectors.

Thank you very much.


Best Regards,

Ahmad Reza


From: Kai Szuttor <kai@icp.uni-stuttgart.de>
Sent: Wednesday, October 28, 2020 9:28 AM
To: Ahmad Reza Motezakker
Cc: espressomd-users@nongnu.org List
Subject: Re: Constraint violated by particle
 
Hi Ahmad,

i guess your normal vectors are pointing in the wrong direction?

Best,

Kai

Am 28.10.2020 um 09:23 schrieb Ahmad Reza Motezakker <armot@kth.se>:



Dear All, 


I have a system of a polymer chain, LB fluid and wall constraints (a small chain of polymer, Two wall for fluid boundary and at the same place two wall constraints for setting up the wall-particle interaction). I make the system in the order of creating the polymer chain, fluid and its LB boundaries (Wall), and constraints. I do not face any error during polymer warming up, equilibration, and fluid-polymer warming up. I define the polymer far from the constraints and add lennard-jones repulsion between the polymer and constraints to avoid any constraint violation. I define the LB boundaries and constraints as follows:

-----------------------------------------------------

logging.info("Setup LB boundaries.")
top_wall = espressomd.lbboundaries.LBBoundary(shape=espressomd.shapes.Wall(normal=[0, 0, -1], dist=0))
bottom_wall = espressomd.lbboundaries.LBBoundary(shape=espressomd.shapes.Wall(normal=[0, 0, 1], dist=50))
system.lbboundaries.add(top_wall)
system.lbboundaries.add(bottom_wall)
#for constraints only
TopWall = Wall(dist=0, normal = (0,0,-1))
BottomWall = Wall(dist = 50, normal=(0,0,1))
system.constraints.add(shape = TopWall, particle_type = 10, penetrable=False)
system.constraints.add(shape = BottomWall, particle_type = 10, penetrable=False)
-----------------------------------------------------
But when I run the integration, in the very very first step (while the polymer is the middle of the box and far from the walls) I face the error : Constraint violated by particle.

Could you please give me some hints on that? I really appreciate your help.

​Best Regards,
Ahmad Reza



<boundaries.pdf>

reply via email to

[Prev in Thread] Current Thread [Next in Thread]